The Indigo® alpha helix model has a mixture of alanine, lysine and serine side groups and is designed to fit the major grooves of the Indigo® 17 base pair DNA model & 36 base pair DNA model with realistic steric hindrance. Available assembled only and guaranteed to have correct handedness.
Or, see the Indigo® Alpha Helix model in Orbit style. It requires assembly but can also be made into a beta pleated sheet.
The size of the major & minor groove in the B DNA helix is very specific since most of the important chemistry takes place there. This model has been designed to fit the major groove by taking into account the steric hindrance that is imposed on the molecule by the atoms in the DNA model. While you can physically squeeze it into the minor groove of our DNA model this would be forbidden in the real thing.
The animation below from Scientific American is particularly well done. However, it doesn't mention the fact that alpha helices are attached in the major groove as anchors & are used in the process of pulling replicating DNA strands apart during cell division.
|60010E||Hydrogen cap, ("mushroom"), ~15mm||88|
|60200E||Atom, Molymod, red (oxygen), 2 hole, 105 degrees||1|
|60210E||Atom, Molymod, white (hydrogen), 2 hole, 180 degree, 17mm||15|
|60211E||Atom, Molymod, red (oxygen), 2 hole, 180 degrees, 17mm||18|
|60310E||Atom, Molymod, black (carbon), 3 hole, 120 degrees, 23mm||18|
|60311E||Atom, Molymod, blue (nitrogen), 3 hole, 120 degrees, 23mm||19|
|60400E||Atom, Molymod, black (carbon), 4 hole, 109.5 degrees, 23mm||40|
|60401E||Atom, Molymod, blue (nitrogen), 4 hole, 109.5 deg., 23mm||1|
|61015E||Bond, Molymod, opaque, 2mm (for spacefilling models)||110|
|61025E||Bond, Molymod, red keylock, 1mm||18|